Yes with the big slower Axis wings (1150 and 1300) on the longer alu mast it became very noticeable, less so on HM which I think is an important note: torsion probably more difficult to pin down and measure but huge impact on big span stability, which I think @McD gives some guidance on.
Also seems sensible to do a few weights from 10-50kg to plot any non-linear flex type stuff?